I'd go with stitchdup's advice if you want to get it done with the least aggravation.
None of the windows in that are compound-curves, so heat-forming isn't necessary.
Single-curved "glass" made from colored clear sheet can be gently curved with your fingers well enough to hold its shape.
Either ignoring a definitive answer from someone who actually knows, or wanting to argue, is a frequent and irksome occurrence, and not conducive to getting the real experts to offer correct info.
But hey...it's just SOP for the interwebs.